Our aim is to evaluate the variability between estimated patient weight (EPW) and actual patient weight (APW), depending on the source of weight estimation (patient, family or hospital staff) and the impact on the ¡°true dose¡± (TD) of iv alteplase administered.
Prospective study of patients with acute ischemic stroke treated consecutively with iv tPA in our institution from May 2010 to May 2011. Alteplase dosing was calculated according to EPW. APW was determined in the 24 hours following iv alteplase treatment.
A total of 72 patients were included. Globally, patient's weight was overestimated: mean=2.49 Kg. Hospital staff overestimated the patient's weight (estimation>10 % of APW) in 45 % of cases; the family overestimated in 14 % of cases, while no patients overestimated their own weight (p=.005). The patients were the most accurate source to establish their actual weight, but also the least used source. The average TD of alteplase was 0.932 mg/Kg.
Dose calculation of alteplase according to EPW leads to variation of the TD, which may affect the safety and effectiveness of the treatment. Whenever possible, the patients¡¯ estimation of their own weight should be taken into consideration. A method to obtain the APW is needed, avoiding the use of visual weight estimation.